Cu-Cr-Zr 合金动态载流力学性能及其修正 Johnson-Cook 模型

To address the inability of traditional constitutive models to characterize the electro-mechanical coupling behavior of materials under current-carrying conditions in mult-i field coupled simulations of electromagnetic rail launch systems, a modified constitutive model incorporating electroplastic effects is proposed to improve computational accuracy. A supercapacitor-based current-carrying circuit is integrated into a split Hopkinson tensile bar experimental platform. High-strain-rate tests are conducted to shorten effective signal durations and mitigate electromagnetic interference. Dynamic tensile tests on Cu-Cr-Zr alloy under varying strain rates and current densities are performed, yielding corresponding stress-strain curves. Experimental results demonstrate that the strength of Cu-Cr-Zr alloy under dynamic tensile conditions is significantly higher than under quas-i static conditions, exhibiting notable strain-rate strengthening effects. As current density increases, flow stress gradually decreases, with a pronounced reduction observed at 5. 7 ×10⁸A/m²In particular, yield strength decreases by 94 MPa and ultimate strength by 177. 9 MPa. Based on experimental data, the Johnson-Cook model is modified by revising its strain-rate hardening term and introducing an electroplasticity term, effectively capturing the material’ s mechanical behavior under dynamic current-carrying tension. The modified model shows strong agreement with experimental curves, with an error of less than 3. 6 9%, providing a valuable reference for mult-i physics computation and material evaluation in electromagnetic energy equipment.